Rolling Tachyons in String Cosmology

TL;DR

This paper investigates the impact of rolling tachyons within string cosmology, deriving solutions in different frames and analyzing their expansion behavior to understand their cosmological implications.

Contribution

It provides explicit flat space solutions in string and Einstein frames, highlighting the decelerating nature of all expanding solutions in the Einstein frame.

Findings

Flat space solutions in string and Einstein frames

All expanding solutions in Einstein frame are decelerating

Insights into tachyon dynamics in cosmological models

Abstract

We study the role of rolling tachyons in the cosmological model with dilatonic gravity. In the string frame, flat space solutions of both initial-stage and late-time are obtained in closed form. In the Einstein frame, we show that every expanding solution is decelerating.